1. Field of the Invention
This invention relates in general to seals for wellhead assemblies, and in particular to an annulus metal seal for a tubing hanger, casing hanger or the like.
2. Description of the Prior Art
In wellheads, seals are used to seal the annulus between concentric inner and outer tubular members. Particularly with subsea wells and high pressure wells, metal seals are desirable. Metal seals will last longer, withstand higher temperatures, and also will seal at higher pressures than elastomeric seals. There are a variety of metal seals. The seals are set or energized by employing a large downward force to cause the seals to deform against the two sealing surfaces.
In some instances, it may desirable to energize two metal seals simultaneously. For example, in a tubing hanger which has a lateral flow passage. Annular seals which locate above and below this passage have in the past been elastomeric seals. Because of axial tolerances and the high forces required for metal-seals, metal seals are not employed for this purpose at this time to applicant's knowledge.